The use of RFID tags and other electronic devices, such as Bluetooth and Zigbee devices, has become prevalent, especially in the management of assets, particularly those applications associated with inventory management. For example, the use of RFID tags permits the monitoring of the production line and the movement of assets or components through the supply chain.
To further illustrate this concept, a manufacturing entity may adhere RFID tags to components as they enter the production facility. These components are then inserted into the production flow, forming sub-assemblies in combination with other components, and finally resulting in a finished product. The use of RFID tags allows the personnel within the manufacturing entity to track the movement of the specific component throughout the manufacturing process. It also allows the entity to be able to identify the specific components that comprise any particular assembly or finished product.
In addition, the use of RFID tags has also been advocated within the drug and pharmaceutical industries. In February 2004, the United States Federal and Drug Administration issued a report advocating the use of RFID tags to label and monitor drugs. This is an attempt to provide pedigree and to limit the infiltration of counterfeit prescription drugs into the market and to consumers.
Since their introduction, RFID tags have been used in many applications, such as to identify and provide information for process control in filter products. U.S. Pat. No. 5,674,381, issued to Den Dekker in 1997, discloses the use of “electronic labels” in conjunction with filtering apparatus and replaceable filter assemblies. Specifically, the patent discloses a filter having an electronic label that has a read/write memory and an associated filtering apparatus that has readout means responsive to the label. The electronic label is adapted to count and store the actual operating hours of the replaceable filter. The filtering apparatus is adapted to allow use or refusal of the filter, based on this real-time number. The patent also discloses that the electronic label can be used to store identification information about the replaceable filter.
A patent application by Baker et al, published in 2005 as U.S. Patent Application Publication No. US2005/0205658, discloses a process equipment tracking system. This system includes the use of RFID tags in conjunction with process equipment. The RFID tag is described as capable of storing “at least one trackable event”. These trackable events are enumerated as cleaning dates, and batch process dates. The publication also discloses an RFID reader that is connectable to a PC or an internet, where a process equipment database exists. This database contains multiple trackable events and can supply information useful in determining “a service life of the process equipment based on the accumulated data”. The application includes the use of this type of system with a variety of process equipment, such as valves, pumps, filters, and ultraviolet lamps.
In addition to RFID tags, the possibility exists to include other electronics in the filtering elements as well. Another patent application, filed by Jornitz et al and published in 2004 as U.S. Patent Application Publication No. 2004/0256328, discloses a device and method for monitoring the integrity of filtering installations.
This publication describes the use of filters containing an onboard memory chip and communications device, in conjunction with a filter housing. The filter housing acts as a monitoring and integrity tester. That application also discloses a set of steps to be used to insure the integrity of the filtering elements used in multi-round housings. These steps include querying the memory element to verify the type of filter that is being used, its limit data, and its production release data.
More and more, other electronics such as sensors, including pressure sensors, temperature sensors and concentration sensors, have also been added to filtering elements to further expand the capabilities of these devices. Co-pending U.S. Patent Application Publication Nos. 2007/0240578, 2007/0243113 and 2007/0240492 all describe additional electronics that can be added to filtering elements to improve system performance and availability.
However, despite the rapid increase in the ability and the desire to add advanced electronics to filtering elements, there remain significant drawbacks. For example, the issue of effectively communicating to an electronic device within a stainless steel (or other metal) housing remains problematic. In some cases, communication can only be effectuated by using an alternate housing material that allows wireless transmissions to pass through it (such as plastic), or by introducing a small window in the housing through which wireless signals can pass. In other cases, wires are fed into the housing to the various components.
A more reliable, minimally intrusive method of communicating with the devices within a housing assembly is needed.